An acceleration control apparatus for a vehicle is known in the art, as disclosed, for example, in Patent Publication No. 2006-506270 of an international patent application published in Japan (International Publication No. WO 2004/045898 A2). According to such a prior art, a desired vehicle acceleration is automatically adjusted by means of controlling an acceleration in a vehicle traveling direction. The above desired vehicle acceleration is obtained by carrying out a feed-forward control and a feedback control at a vehicle acceleration control portion, which is also performing a brake control and an engine control.
In the prior art, however, performance of an acceleration control in the vehicle traveling direction may be decreased, for example, immediately after an ignition switch is turned on, incase of a computing limit of ECU, or when a disturbance such as a temperature change occurs. For example, when a power-train torque estimated by a power-train control portion (such as, an engine ECU, etc.) is used for the feed-forward control, and estimation accuracy for such estimated power-train torque is decreased, an error may be generated in a demand value for an axle torque, which is calculated as a feed-forward component. As a result, the performance of the acceleration control in the vehicle traveling direction is decreased.